The Process Whose Specific Outcome Is the Progression of an Osteoblast Over Time From Its Formation to the Mature Structure. Osteoblast Development Does Not Include the Steps Involved in Committing a Cranial Neural Crest Cell or an Osteoprogenitor Cell to an Osteoblast Fate. an Osteoblast Is a Cell That Gives Rise to Bone.

A Receptor Mediated Endocytosis Process That Results in the Movement of Receptors From the Plasma Membrane to the Inside of the Cell. the Process Begins When Cell Surface Receptors Are Monoubiquitinated Following Ligand Induced Activation. Receptors Are Subsequently Taken Up Into Endocytic Vesicles From Where They Are Either Targeted to the Lysosome or Vacuole For Degradation or Recycled Back to the Plasma Membrane.

The Chemical Reactions and Pathways Resulting in the Breakdown of Any of a Group of Substances That Are Released On Excitation From the Axon Terminal of a Presynaptic Neuron of the Central or Peripheral Nervous System and Travel Across the Synaptic Cleft to Either Excite or Inhibit the Target Cell.

The Process Whose Specific Outcome Is the Progression of the Retina Over Time From Its Formation to the Mature Structure. the Retina Is the Innermost Layer or Coating At the Back of the Eyeball Which Is Sensitive to Light and in Which the Optic Nerve Terminates.

The Space External to the Outermost Structure of a Cell. For Cells Without External Protective or External Encapsulating Structures This Refers to Space Outside of the Plasma Membrane. This Term Covers the Host Cell Environment Outside an Intracellular Parasite.

A Compound Membranous Cytoplasmic Organelle of Eukaryotic Cells Consisting of Flattened Ribosome Free Vesicles Arranged in a More or Less Regular Stack. the Golgi Apparatus Differs From the Endoplasmic Reticulum in Often Having Slightly Thicker Membranes Appearing in Sections As a Characteristic Shallow Semicircle So That the Convex Side (cis or Entry Face) Abuts the Endoplasmic Reticulum Secretory Vesicles Emerging From the Concave Side (trans or Exit Face). in Vertebrate Cells There Is Usually One Such Organelle While in Invertebrates and Plants Where They Are Known Usually As Dictyosomes There May Be Several Scattered in the Cytoplasm. the Golgi Apparatus Processes Proteins Produced On the Ribosomes of the Rough Endoplasmic Reticulum; Such Processing Includes Modification of the Core Oligosaccharides of Glycoproteins and the Sorting and Packaging of Proteins For Transport to a Variety of Cellular Locations. Three Different Regions of the Golgi Are Now Recognized Both in Terms of Structure and Function: Cis in the Vicinity of the Cis Face Trans in the Vicinity of the Trans Face and Medial Lying Between the Cis and Trans Regions.

A Cellular Component That Forms a Specialized Region of Connection Between Two or More Cells or Between a Cell and the Extracellular Matrix. At a Cell Junction Anchoring Proteins Extend Through the Plasma Membrane to Link Cytoskeletal Proteins in One Cell to Cytoskeletal Proteins in Neighboring Cells or to Proteins in the Extracellular Matrix.

The Component of a Membrane Consisting of the Gene Products That Are Tethered to the Membrane Only by a Covalently Attached Anchor Such As a Lipid Group That Is Embedded in the Membrane. Gene Products with Peptide Sequences That Are Embedded in the Membrane Are Excluded From This Grouping.

The Junction Between the Axon of a Motor Neuron and a Muscle Fiber. in Response to the Arrival of Action Potentials the Presynaptic Button Releases Molecules of Neurotransmitters Into the Synaptic Cleft. These Diffuse Across the Cleft and Transmit the Signal to the Postsynaptic Membrane of the Muscle Fiber Leading to a Change in Post Synaptic Potential.

The Junction Between a Nerve Fiber of One Neuron and Another Neuron or Muscle Fiber or Glial Cell; the Site of Interneuronal Communication. As the Nerve Fiber Approaches the Synapse It Enlarges Into a Specialized Structure the Presynaptic Nerve Ending Which Contains Mitochondria and Synaptic Vesicles. At the Tip of the Nerve Ending Is the Presynaptic Membrane; Facing It and Separated From It by a Minute Cleft (the Synaptic Cleft) Is a Specialized Area of Membrane On the Receiving Cell Known As the Postsynaptic Membrane. in Response to the Arrival of Nerve Impulses the Presynaptic Nerve Ending Secretes Molecules of Neurotransmitters Into the Synaptic Cleft. These Diffuse Across the Cleft and Transmit the Signal to the Postsynaptic Membrane.

Interacting Selectively and Non Covalently with Collagen a Group of Fibrous Proteins of Very High Tensile Strength That Form the Main Component of Connective Tissue in Animals. Collagen Is Highly Enriched in Glycine (some Regions Are 33% Glycine) and Proline Occurring Predominantly As 3 Hydroxyproline (about 20%).

Catalysis of the Hydrolysis of a Substrate by a Catalytic Mechanism That Involves a Catalytic Triad Consisting of a Serine Nucleophile That Is Activated by a Proton Relay Involving an Acidic Residue (e.g. Aspartate or Glutamate) and a Basic Residue (usually Histidine).

Interacting Selectively and Non Covalently with Acetylcholine an Acetic Acid Ester of the Organic Base Choline That Functions As a Neurotransmitter Released At the Synapses of Parasympathetic Nerves and At Neuromuscular Junctions.